Performance Analysis of Hybrid Electric Vehicle Thermal Management System

This research articulates the architecture, simulation, and performance assessment of a sophisticated integrated thermal management system (ITMS) tailored for battery electric vehicles (EVs), designed to proficiently control the thermal conditions of essential components—including the battery pack, electric motor, power electronics (inverter, charger, DC-DC converter), and passenger compartment—under severe environmental conditions. The proposed system incorporates adaptable coolant circuits regulated by a four-way valve, facilitating dynamic transitions between serial mode (to recover waste heat in cold climates) and parallel mode (to maximize cooling efficacy in high temperatures), in conjunction with a vapor compression refrigeration cycle utilizing R-134a and a 50:50 water-ethylene glycol coolant blend. A predominantly reactive control methodology, enhanced with PI controllers for cabin and compressor management, guarantees swift response, stability, and energy efficiency. The system was modeled and meticulously evaluated in MATLAB/Simulink through a rigorous 3600-second real-world driving scenario under ambient temperatures of 40 °C and –10 °C, with the cabin temperature target maintained at 21 °C via full recirculation. Results indicate exceptional thermal management: cabin temperature stability within ±0.6 °C in elevated conditions and rapid heating with ±0.8 °C stability in lower conditions; battery temperature consistently maintained between 25–35 °C with cell uniformity under 2.8 °C; and secure operation of powertrain components. In cold conditions, serial mode and complete bypassing reduced parasitic losses by disabling refrigeration and utilizing motor waste heat. The proposed ITMS demonstrates resilient performance on par with industry standards while providing simplicity benefits, significantly enhancing EV range retention, passenger comfort, battery lifespan, and overall energy efficiency across various operating scenarios.